CN104494464A - Multi-motor coordination controller for distributed driving electric automobile - Google Patents

Abstract

The invention discloses a multi-motor coordination controller for a distributed driving electric automobile. The multi-motor coordination controller designs three corresponding driving modes of economy, stability, and dynamic property for different driving structures, and a fault-tolerant mode conforming to characteristics of the driving structures; the driving coordination controller is connected with a whole automobile controller and a plurality of motor controllers through a CAN bus; a layered structure of the whole automobile controller, the driving coordination controller and the motor controllers is adopted; the driving coordination controller is arranged between the whole automobile controller on the upper layer and the motor controllers on the lower layer, is responsible for receiving driving requirement signals, steering requirement signals, configuration form signals and functional mode signals of the whole automobile controller, considers manufacturing and type selection difference of the motors for preset at the same time, and dynamically adjusts driving torques of the motors to meet whole automobile driving and steering requirements under different functional modes. The multi-motor coordination controller effectively improves the safety and the controllability of the distributed driving electric automobile, and deepens industrial division.

Description

A kind of distributed-driving electric automobile multi-motor coordination controller

Technical field

The invention belongs to electronlmobil drived control field, be specifically related to a kind of distributed-driving electric automobile multi-motor coordination controller.

Background technology

In recent years, due to environmental protection, the becoming increasingly conspicuous of energy security two fold problem, electronlmobil leaps to the visual field of people again.Simultaneously, along with the development of power electronics control technology and computer technology, the developing direction of electrified, intelligent future automobile beyond doubt, and adopt the distributed driving automobile of wheel limit or In-wheel motor driving with its comparatively outstanding controller performance, be subject to the common concern of academia and engineering circles.

Adopt the distributed driving automobile of wheel limit or In-wheel motor driving, battery is connected by cable with drive motor, each wheel can be driven separately by wheel limit or wheel hub motor, give up traditional mechanical connection each other, eliminate the parts such as driving engine, fuel tank, power-transfer clutch, change-speed box, transmission shaft, diff.Each motor is controlled by corresponding controller, and the communication between each controller realizes by CAN.Obviously, for the battery-driven car of distributed driving, the performance of its superior handling be based upon precise coordination control carried out to the torque and rotational speed of each motor basis on, therefore, the cooperation control of each drive motor then becomes the crucial common technology of of distributed driving battery-driven car.

At present, the realization of motor coordination control policy is responsible for by car load factory substantially, its way studies motor coordination control policy by car load factory and strategy is write entire car controller, and control each motor action by entire car controller by CAN, the electronlmobil on domestic and international market there's no one who doesn't or isn't in this way.This state has its corresponding defect: one is the management function of entire car controller and the controlling functions of specific features are mixed, add the degree of coupling of entire car controller and vehicle, be unfavorable for being formed the research and development of independently entire car controller industry and integrated vehicle control tactics; Two is that the function of entire car controller is too concentrated, and system maintainability is poor, and adds the danger of system to a certain extent along with the application of individual drive of many wheels and the development of intelligent vehicle.

In view of above problem, be necessary to develop the tuning controller of the torque coordination distribution being responsible for each motor specially, current motor coordination control policy is separated from entire car controller, make entire car controller only be responsible for the management function of vehicle, such as motor torque control, coordination function are then served as by driving tuning controller.

Summary of the invention

The object of the invention is the problem that two and above drive motor in order to solve distributed driving battery-driven car coordinate mutually, provide a kind of distributed-driving electric automobile multi-motor coordination controller, it can send command adapted thereto according to the instruction of vehicle safety, stability requirement and chaufeur or entire car controller to lower floor's electric machine controller, controls the running state of each drive motor.

For achieving the above object, the present invention adopts following technical scheme:

A kind of distributed-driving electric automobile multi-motor coordination controller, entire car controller, driving tuning controller and some electric machine controllers for controlling corresponding motor are by CAN network service, wherein, entire car controller is responsible for all decision tasks, receive chaufeur input and the status information of car load, calculate the driving of chaufeur and turn to demand, identification travel condition of vehicle select configuration and functional mode; Tuning controller is driven to be responsible for torque coordination, receive the driving desired signal of entire car controller, turn to desired signal, configuration signal and functional mode signal, consider the property difference of each motor simultaneously, dynamically send torque instruction to each electric machine controller and drive with the car load met under different functional modes and turn to demand; Execution is responsible for by some electric machine controllers, receives the dtc signal driving tuning controller, realizes torque closed loop control.

The present invention further improves and is: described configuration comprises antero posterior axis individual drive, front-wheel individual drive, trailing wheel individual drive and four motorized wheels, and the functional mode of often kind of configuration includes stable mode, economic model, dynamic mode and fault-tolerant mode; Drive tuning controller to meet the torque coordination demand of the distributed-driving electric automobile of various configuration, its concrete operations realizing torque co-ordinated control are:

Often kind of configuration becomes a module separately, be respectively antero posterior axis individual drive module, front-wheel individual drive module, trailing wheel individual drive module and four motorized wheels module, meanwhile, each module installation interface, receives from entire car controller configuration information; User selects when dispatching from the factory according to vehicle configuration, directly will the structure parameters of tuning controller be driven to be cured as a default value, or directly arranges structure parameters in entire car controller inside, be sent to driving tuning controller before vehicle start.

The present invention further improves and is: for the configuration that antero posterior axis individual drive, front-wheel individual drive, trailing wheel individual drive and four motorized wheels 4 kinds is different, according to running car requirement, dynamic property, economy, functional mode that stability three kinds is different are set respectively; Often kind of configuration electronlmobil to be chosen any one kind of them in dynamic property, economy, stability pattern according to car body motoring condition or driver intention the functional mode of applicable real time status; Simultaneously according to vehicle safety requirement, fault-tolerant mode is set, when motor or electric machine controller et out of order, automatically starts fault-tolerant mode, the safety traffic of preferential support vehicles; Often kind of corresponding drived control strategy separately of functional mode, and have a module of one's own; Often kind of functional mode arranges an interface, and the functional mode received from entire car controller selects information.

The present invention further improves and is: the property difference considering each motor in torque coordination, specific as follows:

1) the left and right manufacture of two motors and the difference of running environment is considered, arrange in the vehicle of drive motor at left and right sides, this vehicle comprises front-wheel individual drive, trailing wheel individual drive and four motorized wheels, according to the Bench calibration data initialization torque moment offset of real vehicle, ensureing that two, left and right motor exports identical torque same to fixing, reaching identical control accuracy;

2) the type selecting difference of antero posterior axis motor is considered, arrange in the vehicle of drive motor at antero posterior axis, this vehicle comprises antero posterior axis individual drive and four motorized wheels, the efficiency characteristic of preset each motor, under economy mode, ensure that each motor runs on the high performance interval of respective efficiency, under dynamic property pattern, ensure that each motor exports maximum torque.

Hinge structure, the present invention has following beneficial effect:

The present invention can make entire car controller and motor coordination controller two parts depart from car load and accomplish standardization and normalisation.From technical standpoint, first, adopt tuning controller to reduce the coupling of each module, deepened the degree of specialization of technical study; Secondly, relatively original entire car controller centralized control, decentralised control serves the effect of scattering of risk, enhances the reliability of system; Finally, because cooperation control is independent as an independent control unit, when a problem occurs, can directly keeps in repair this module, and entire car controller need not be dismantled, thus enhance the maintainability of system.From the angle of industrialization, each module will form independently industry, deepen specialization, be conducive to raising labour productivity.

Accompanying drawing explanation

Fig. 1 is entire car controller, the connection diagram driving tuning controller and each electric machine controller.

Fig. 2 is the soft and hardware modular construction schematic diagram driving tuning controller.

Fig. 3 drives tuning controller control flow chart.

Fig. 4 is stability control algorithm constructional drawing.

Detailed description of the invention

Below in conjunction with accompanying drawing, invention is described in further detail.

A kind of distributed-driving electric automobile multi-motor coordination of the present invention controller is a tuning controller (as shown in Figure 2) designed for distributed driving battery-driven car.Wherein, distributed driving battery-driven car comprises the distributed driving vehicle of more than two-wheeled and two-wheeled.

As shown in Figure 1, entire car controller 1, driving tuning controller 2 and the near front wheel electric machine controller 3, left rear wheel electric machine controller 4, off front wheel electric machine controller 5 and off hind wheel electric machine controller 6 are connected by CAN.Entire car controller 1 issues dependent instruction by CAN, drives tuning controller 2 to receive the instruction and data that CAN sends, runs corresponding control algorithm, then send torque instruction by CAN respectively to each electric machine controller.

As shown in Figure 2, hardware and software module thereof that the present invention drives tuning controller 2 has been indicated.Hardware layer comprises process chip, CAN interface circuit, feed circuit, memory device, jtag interface and reserved analog quantity I/O interface.Wherein, CAN interface circuit is mainly used in the communication driving tuning controller 2 and entire car controller 1, each electric machine controller and other electronic control unit; The memory device of expansion is used for preset value in slack storage program design and obtains related data and form; Jtag interface is then for driving debugging or the diagnosis of tuning controller 2 program; Analog quantity I/O interface is reserved opening.

As shown in Figure 3, in figure, software layer mainly comprises the drive control module to the configuration module of each configuration battery-driven car and corresponding economy, stability, dynamic property three kinds of functional modes.Each module installation interface is to receive the instruction from top level control device.If automobile configuration is four motorized wheels 4WID form, only need select four motorized wheels 4WID configuration in entire car controller 1 and lock this option.The functional mode and fault-tolerant mode that meet himself configuration characteristic is comprised in often kind of automobile configuration module.In running car, manipulate view integration by entire car controller 1 according to real time running situation and chaufeur and judge, select suitable functional mode and send command adapted thereto to driving tuning controller 2.For stable mode, because the travel conditions of vehicle is comparatively complicated, cause the reason of vehicle unstability more, desirable yaw velocity and side slip angle are parameter, (sensor cost is considered according to the driving parameters that current steering wheel angle and speed meter calculate ideally, side slip angle can adopt observer to estimate), then the value of feedback of itself and auto model is contrasted, if differ comparatively large with ideal value, select stable mode.As for the selection of dynamic mode, then can be intended to according to the manipulation of chaufeur, as arranged a certain threshold values to the aperture of efp, exceed this threshold values and then selecting to enter dynamic mode.Then economic model is selected under default conditions.Here it is emphasized that the selection of which kind of functional mode judges to have been come by entire car controller 1, drive tuning controller 2 to be only responsible for performing the mode instruction of entire car controller 1 here.

If the near front wheel electric machine controller 3, left rear wheel electric machine controller 4, off front wheel electric machine controller 5, off hind wheel electric machine controller 6 or motor break down, then tuning controller 2 is driven to select corresponding fault handling strategy according to corresponding automobile configuration.As the front-wheel of four motorized wheels 4WID configuration or a certain motor of trailing wheel break down, the changeable whole vehicle functions pattern of tuning controller 2 is driven to be back-wheel drive or f-w-d, make car load dynamic balnce, ensure the normal traveling of vehicle, and in real time by transmitting fault information to the highlighted display of full-vehicle control panel to inform chaufeur corresponding failure situation.

After driving tuning controller 2 receives economic model instruction, the opening degree instruction of the efp from entire car controller 1, electronic brake pedal can be received simultaneously, and calculate target torque value according to command value and be sent to each electric machine controller.Due to motor low regime and low torque district efficiency lower, near specified output characteristic curve, there is high efficiency.Based on this characteristic, low speed low torque output area should be avoided when motor runs as far as possible.In addition, consider actual travel situation, during straight-line travelling, left and right wheels propulsive effort should keep balance, therefore the torque distribution problem between wheel can be reduced to the torque distribution problem between antero posterior axis.From above 2, in given demand torque situation, economy objectives can distribute realization by the torque optimization between antero posterior axis.Here arrive the output minimum torque of motor side for objective function with conversion, whole optimization problem is expressed as follows:

Optimal Parameters: antero posterior axis torque distribution coefficient lambda

Objective function: T=λ T _need/ η (λ T _need, n _f)+(1-λ) T _need/ η ((1-λ) T _need, n _r)

Constraint condition: $\left\{\begin{array}{c}\mathrm{\λ}{T}_{\mathrm{need}}\≤\min \left(\right|T_{\max }|,|T_{\mathrm{limf}}\left|\right);(1-\mathrm{\λ})T_{\mathrm{need}}\≤\min \left(\right|T_{\max }|,|T_{\mathrm{limr}}\left|\right)\\ 0\≤\mathrm{\λ}\≤0.5\\ n_r/n_f=\cos \mathrm{\δ}\end{array}\right.$

Wherein, δ is wheel turning angle; η is electrical efficiency characteristic curve; T _needfor the torque of chaufeur input demand; T _maxfor motor torque exports maxim; T _limfand T _limrfor the Driving Torque of motor when front and back wheel reaches limit of adhesion; n _fand n _rfor the rotating speed of antero posterior axis under two-wheeled steering model.

The optimum allocation coefficient under different torque and speed conditions can be calculated according to above analysis, make automobile substantially be in single shaft in low speed low torque region and drive, and be antero posterior axis mean allocation substantially in high speed high torque (HT) region.

Under stable mode, direct yaw moment control (DYC) is adopted to improve the stability of automobile.Its key is by differentiating that travel condition of vehicle calculates a desirable active yaw torque, and choosing of its control variable can be obtained by analysis 2DOF reference model with nominal value, and its expression formula is as follows:

${\mathrm{\γ}}_d=\min \left\{\right|\frac{u}{L(1+K{u}^2)}\mathrm{\δ}|,|\frac{0.85\mathrm{\μg}}{u}\left|\right\}\mathrm{sign}\left(\mathrm{\δ}\right)$

${\mathrm{\β}}_d=\min \left\{\right|\frac{b+{\mathrm{mau}}^2/{\mathrm{LK}}_r}{L(1+K{u}^2)}\mathrm{\δ}|,|{\tan }^{-1}\left(0.02\mathrm{\μg}\right)\left|\right\}\mathrm{sign}\left(\mathrm{\δ}\right)$

Wherein, β _ddesirable side slip angle; γ _dfor desirable yaw velocity; for stability factor; U is the longitudinal velocity of vehicle under vehicle body system of axes; L is antero posterior axis wheelbase; μ is ground attaching coefficient; A, b are respectively the distance of barycenter to antero posterior axis; M is entire vehicle quality; k _f, k _rbe respectively axle cornering stiffness.

As shown in Figure 4, the torque that yaw moment does not get involved vehicle in front distributes between antero posterior axis according to driver pedal input, the torque increment that DYC exports four-wheel is obtained by the feedback of yaw velocity and side slip angle, and the torque being superimposed upon antero posterior axis exports the torque control value obtaining four wheels.According to the analysis to control variable, Δ γ reflects vehicle running state, by differentiate turn to and Δ γ positive and negative, corresponding control effort can be applied, if vehicle left-hand rotation oversteer (Δ γ > 0), by increasing left motor controller 3,4 drive torque value, and the drive torque value of corresponding minimizing right motor controller 5,6 obtains clws compensation yaw moment, is corrected on the track of expectation by vehicle.Moreover, from tire characteristics, cross large driving force when slippage rate and can decline on the contrary, continue to increase torque and can not produce larger yaw moment, so arrange slippage rate controller to export the saturated upper limit exported as DYC.Final torque command sends to 4 electric machine controllers by CAN, ensures that vehicle is meeting smooth operation under chaufeur driving requirement.

Under dynamic mode, this controller adopts Model following control (MFC) method to realize Anti-slip regulation and controls, and this control method does not need other sensor additional, only needs motor torque and tach signal can realize the target of Anti-slip regulation.Its desirable Controlling model is:

$G\left(s\right)=\frac{1}{m+m_w}\frac{1}{s}$

Wherein, m is the complete vehicle quality of 1/4 auto model; j _wfor vehicle wheel rotation inertia, R is radius of wheel;

Meanwhile, be protection motor, power of motor threshold limit value is set in the controller according to motor characteristic.Consider actual travel situation, during straight-line travelling, left and right wheels propulsive effort should keep balance, therefore to adopt in left and right wheels drive torque smaller value as final Driving Torque value.Thus, drive tuning controller 2 to trackslip, under the condition that is no more than power of motor limit value, export larger driving power, obtain good tractive performance ensureing not produce.

Claims (4)

1. a distributed-driving electric automobile multi-motor coordination controller, it is characterized in that: entire car controller (1), driving tuning controller (2) and some electric machine controllers for controlling corresponding motor are by CAN network service, wherein, entire car controller (1) is responsible for all decision tasks, receive chaufeur input and the status information of car load, calculate the driving of chaufeur and turn to demand, identification travel condition of vehicle select configuration and functional mode; Tuning controller (2) is driven to be responsible for torque coordination, receive the driving desired signal of entire car controller, turn to desired signal, configuration signal and functional mode signal, consider the property difference of each motor simultaneously, dynamically send torque instruction to each electric machine controller and drive with the car load met under different functional modes and turn to demand; Execution is responsible for by some electric machine controllers, receives the dtc signal driving tuning controller (2), realizes torque closed loop control.

2. a kind of distributed-driving electric automobile multi-motor coordination controller as claimed in claim 1, it is characterized in that: described configuration comprises antero posterior axis individual drive (FRID), front-wheel individual drive (FWID), trailing wheel individual drive (RWID) and four motorized wheels (4WID), and the functional mode of often kind of configuration includes stable mode, economic model, dynamic mode and fault-tolerant mode; Drive tuning controller (2) to meet the torque coordination demand of the distributed-driving electric automobile of various configuration, its concrete operations realizing torque co-ordinated control are:

Often kind of configuration becomes a module separately, be respectively antero posterior axis individual drive (FRID) module, front-wheel individual drive (FWID) module, trailing wheel individual drive (RWID) module and four motorized wheels (4WID) module, and embedded driving tuning controller (2), simultaneously, each module installation interface, receives from entire car controller configuration information; User selects when dispatching from the factory according to vehicle configuration, directly will the structure parameters of tuning controller (2) be driven to be cured as a default value, or select in man-machine interface or directly structure parameters be set in entire car controller inside, being sent to before vehicle start and driving tuning controller (2).

3. a kind of distributed-driving electric automobile multi-motor coordination controller as claimed in claim 2, it is characterized in that: for the configuration that antero posterior axis individual drive (FRID), front-wheel individual drive (FWID), trailing wheel individual drive (RWID) and four motorized wheels (4WID) 4 kinds are different, according to running car requirement, dynamic property, economy, functional mode that stability three kinds is different are set respectively; Often kind of configuration electronlmobil to be chosen any one kind of them in dynamic property, economy, stability pattern according to car body motoring condition or driver intention the functional mode of applicable real time status; Simultaneously according to vehicle safety requirement, fault-tolerant mode is set, when motor or electric machine controller et out of order, automatically starts fault-tolerant mode, the safety traffic of preferential support vehicles; Often kind of corresponding drived control strategy separately of functional mode, and have a module of one's own, embed and drive tuning controller (2); Often kind of functional mode arranges an interface, and the functional mode received from entire car controller selects information.

4. a kind of distributed-driving electric automobile multi-motor coordination controller as claimed in claim 2, is characterized in that: the property difference taking into full account each motor in torque coordination, specific as follows:

1) the left and right manufacture of two motors and the difference of running environment is considered, arrange in the vehicle of drive motor at left and right sides, this vehicle comprises front-wheel individual drive (FWID), trailing wheel individual drive (RWID) and four motorized wheels (4WID), according to the Bench calibration data initialization torque moment offset of real vehicle, ensureing that two, left and right motor exports identical torque same to fixing, reaching identical control accuracy;

2) the type selecting difference of antero posterior axis motor is considered, arrange in the vehicle of drive motor at antero posterior axis, this vehicle comprises antero posterior axis individual drive (FRID) and four motorized wheels (4WID), the efficiency characteristic data of preset each motor, under economy mode, ensure that each motor runs on the high performance interval of respective efficiency, under dynamic property pattern, ensure that each motor exports maximum torque.